From clones to immunopeptidomes: New developments in the characterization of permissive HLA-DP mismatches in hematopoietic cell transplantation.

Mismatching at the HLA-DPB1 locus occurs frequently in hematopoietic cell transplantation with unrelated donors. Despite this, HLA-DPB1 allelic mismatches have traditionally not been considered in patient-donor matching. A T-cell epitope (TCE) model for the functional assessment of permissive mismatches at this locus has nevertheless been adopted in clinical practice. While initially based on a hierarchical immunogenicity elucidated from allorecognition by T-cell clones isolated from a patient, newer developments in the understanding of this model's biological basis, including a central role for immunopeptidome divergence between mismatched allotypes, have prompted changes in the assignment of permissiveness, providing the opportunity for a more granular evaluation of graft-versus-host disease and relapse risks according to the nature and directionality of permissive mismatches. How these advances impact the assessment of permissiveness at HLA-DPB1 and potentially the intelligent selection of donors according to the main clinical goal for different patients is the subject of the present review.

Association between specific human leukocyte antigen alleles and development of thyroid immune-related adverse event.

Aim: Inherent variations in human leukocyte antigen (HLA) alleles have been revealed epidemiologically to influence the development of autoimmune diseases. HLA alleles may thus also be associated with the development of immune-related adverse events (irAEs), such as thyroid irAE.Materials & methods: In this case-control study, 71 cancer patients who received immune checkpoint inhibitors were enrolled and HLA-genotyped and the frequency of HLA alleles was compared.Results: A*26:01, DPA1*01:03 and DPB1*02:01 were significantly more frequent in patients with thyroid irAE than in patients without any irAEs (35.0 vs 3.2% [p = 0.004], 80.0 vs 45.2% [p = 0.020] and 55.0 vs 25.8% [p = 0.044], respectively).Conclusion: A*26:01, DPA1*01:03 and DPB1*02:01 appear to be associated with thyroid irAE.

Everyone has a unique combination of human leukocyte antigens (HLAs) in their body that help the immune system identify threats. HLAs were named from the fact that they were first identified on the surface of human leukocytes. Afterward, HLAs were also found on all human cells. HLAs present antigens to immune cells. These HLAs also influence how the immune system attacks cancer cells. Immune checkpoint inhibitors are drugs that can help the immune system fight cancer, but they sometimes cause severe adverse events. In this study, we investigated whether specific HLA genes are related to the development of an adverse event that affects the thyroid in cancer patients treated with immune checkpoint inhibitors. We found an association between three HLA genes (A*26:01, DPA1*01:03 and DPB1*02:01) and the development of the thyroid adverse event. However, larger studies are needed to confirm and generalize these initial exploratory findings.

Massive digital gene expression analysis reveals different predictive profiles for immune checkpoint inhibitor therapy between adenocarcinoma and squamous cell carcinoma of advanced lung cancer.

BACKGROUND: Immune checkpoint inhibitors prolong the survival of non-small cell lung cancer (NSCLC) patients. Although it has been acknowledged that there is some correlation between the efficacy of anti-programmed cell death-1 (PD-1) antibody therapy and immunohistochemical analysis, this technique is not yet considered foolproof for predicting a favorable outcome of PD-1 antibody therapy. We aimed to predict the efficacy of nivolumab based on a comprehensive analysis of RNA expression at the gene level in advanced NSCLC. METHODS: This was a retrospective study on patients with NSCLC who were administered nivolumab at the Kansai Medical University Hospital. To identify genes associated with response to anti-PD-1 antibodies, we grouped patients into responders (complete and partial response) and non-responders (stable and progressive disease) to nivolumab therapy. Significant genes were then identified for these groups using Welch's t-test. RESULTS: Among 42 analyzed cases (20 adenocarcinomas and 22 squamous cell carcinomas), enhanced expression of MAGE-A4, BBC3, and OTOA genes was observed in responders with adenocarcinoma, and enhanced expression of DAB2, HLA-DPB,1 and CDH2 genes was observed in responders with squamous cell carcinoma. CONCLUSIONS: This study predicted the efficacy of nivolumab based on a comprehensive analysis of mRNA expression at the gene level in advanced NSCLC. We also revealed different gene expression patterns as predictors of the effectiveness of anti PD-1 antibody therapy in adenocarcinoma and squamous cell carcinoma.

SARS-CoV-2 mRNA vaccination elicits a robust and persistent T follicular helper cell response in humans.

SARS-CoV-2 mRNA vaccines induce robust anti-spike (S) antibody and CD4+ T cell responses. It is not yet clear whether vaccine-induced follicular helper CD4+ T (TFH) cell responses contribute to this outstanding immunogenicity. Using fine-needle aspiration of draining axillary lymph nodes from individuals who received the BNT162b2 mRNA vaccine, we evaluated the T cell receptor sequences and phenotype of lymph node TFH. Mining of the responding TFH T cell receptor repertoire revealed a strikingly immunodominant HLA-DPB1∗04-restricted response to S167-180 in individuals with this allele, which is among the most common HLA alleles in humans. Paired blood and lymph node specimens show that while circulating S-specific TFH cells peak one week after the second immunization, S-specific TFH persist at nearly constant frequencies for at least six months. Collectively, our results underscore the key role that robust TFH cell responses play in establishing long-term immunity by this efficacious human vaccine.

Influence of HLA Class II Alleles and DRB1-DQB1 Haplotypes on Rheumatoid Arthritis Susceptibility and Autoantibody Status in the Chinese Han Population.

Human leukocyte antigen (HLA) class II alleles are considered to play a key role in the progress of rheumatoid arthritis (RA). This study was carried out to investigate the presence of HLA class II alleles and their influence on disease risk and autoantibody status in Chinese Han patients with RA. Here, HLA-DRB1, DQB1 and DPB1 genotyping was performed in 125 RA patients and 120 healthy controls by using the next-generation sequencing (NGS). Strong positive associations were shown between high-resolution typed HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01, DPB1*02:01:02 and RA patients. Moreover, the haplotypes HLA-DRB1*04:05:01~ DQB1*04:01:01 and HLA-DRB1*10:01:01~ DQB1*05:01:01 were found to be more frequent in RA populations than in healthy controls. These possible susceptible HLA alleles (HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01 and DPB1*02:01:02) also showed higher frequencies in seropositive RA patients as compared to normal controls. The present study provided evidence that alleles HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01 and DPB1*02:01:02 constituted RA risk alleles, and haplotypes HLA-DRB1*04:05:01~ DQB1*04:01:01, HLA-DRB1*10:01:01~ DQB1*05:01:01 also showed prevalence in Chinese Han patients with RA. Serological results preliminary demonstrated patients carrying RA-risk HLA alleles might elevate the serum level of anti-citrullinated protein antibodies and rheumatoid factor and affect RA progression.

Predicting HLA-DPB1 permissive probabilities through a DPB1 prediction service towards the optimization of HCT donor selection.

Despite its demonstrated importance in hematopoietic cell transplantation, the HLA-DPB1 locus is only typed in one in five unrelated donors in the United States. Addressing this issue, we developed a DPB1 Prediction Service that leverages seven-locus haplotype frequencies (HLA-A ∼ C ∼ B ∼ DRB3/4/5 ∼ DRB1 ∼ DQB1 ∼ DPB1) to extend the imputation of six-locus HLA typing (HLA-A ∼ C ∼ B ∼ DRB3/4/5 ∼ DRB1 ∼ DQB1) to the HLA-DPB1 locus, including the novel prediction of HLA-DPB1 TCE groups to calculate donor-recipient TCE permissive match probabilities. Simulations of current-day patient searches reveal the service can fill in missing gaps for another four in five donors that appears on lists. To validate its performance, samples of 206,328 registered donors and 5,218 donor-recipient pairs with known high-resolution HLA-DPB1 typing were used for predicted-versus-observed comparisons. These comparisons demonstrated that the predictions were correct for 11.9-19.7% of HLA-DPB1 genotypes, 64.9-70.0% of TCE groups, and 61.0% of permissive match categories. Although HLA-DPB1 match predictions must be confirmed by additional typing, knowledge of TCE match probabilities facilitates rapid and improved identification of best donor options, especially for populations of color. Thus, we developed the TCE Prediction Tool user interface for a pilot program with several transplant centers to preview the accuracy and utility of this prediction framework, which provides valuable upfront optimization of donor selection.

HLA-DPB1 rs9277535 polymorphism is associated with rheumatoid arthritis risk in a Chinese Han population.

We used a custom-by-design 48-Plex single nucleotide polymorphism scan™ kit to investigate the relationship between susceptibility to rheumatoid arthritis (RA) and HLA-DPB1 rs9277535 polymorphism in 805 RA patients and 1095 healthy controls from the Chinese Han population. Blood plasma levels of HLA-DPB1 were also examined using enzyme-linked immunosorbent assays in 170 RA patients and 170 matched control individuals. Quantitative reverse transcription PCR (qRT-PCR) was used to evaluate relative HLA-DPB1 mRNA levels in these blood samples as well. The results indicated that some HLA-DPB1 rs9277535 polymorphisms decreased RA susceptibility. Stratified analysis indicated that risk of RA decreased specifically in women and those who were at least 55 years old. In addition, the AG and GG+AG genotypes were associated with CRP status, ACPA status, and ESR in RA patients when the AA genotype was used as the reference group. Furthermore, average HLA-DPB1 plasma levels were increased in RA patients, and HLA-DPB1 plasma levels and mRNA expression were lower in those with the GG genotype than in those with the AA genotype. These results indicate that HLA-DPB1 rs9277535 polymorphism is associated with a decreased risk of RA in the Chinese population.

Beryllium-specific CD4+ T cells induced by chemokine neoantigens perpetuate inflammation.

Discovering dominant epitopes for T cells, particularly CD4+ T cells, in human immune-mediated diseases remains a significant challenge. Here, we used bronchoalveolar lavage (BAL) cells from HLA-DP2-expressing patients with chronic beryllium disease (CBD), a debilitating granulomatous lung disorder characterized by accumulations of beryllium-specific (Be-specific) CD4+ T cells in the lung. We discovered lung-resident CD4+ T cells that expressed a disease-specific public CDR3ß T cell receptor motif and were specific to Be-modified self-peptides derived from C-C motif ligand 4 (CCL4) and CCL3. HLA-DP2-CCL/Be tetramer staining confirmed that these chemokine-derived peptides represented major antigenic targets in CBD. Furthermore, Be induced CCL3 and CCL4 secretion in the lungs of mice and humans. In a murine model of CBD, the addition of LPS to Be oxide exposure enhanced CCL4 and CCL3 secretion in the lung and significantly increased the number and percentage of CD4+ T cells specific for the HLA-DP2-CCL/Be epitope. Thus, we demonstrate a direct link between Be-induced innate production of chemokines and the development of a robust adaptive immune response to those same chemokines presented as Be-modified self-peptides, creating a cycle of innate and adaptive immune activation.

Changes in epigenetic profiles throughout early childhood and their relationship to the response to pneumococcal vaccination.

BACKGROUND: Pneumococcal infections are a major cause of morbidity and mortality in young children and immaturity of the immune system partly underlies poor vaccine responses seen in the young. Emerging evidence suggests a key role for epigenetics in the maturation and regulation of the immune system in health and disease. The study aimed to investigate epigenetic changes in early life and to understand the relationship between the epigenome and antigen-specific antibody responses to pneumococcal vaccination. METHODS: The epigenetic profiles from 24 healthy children were analyzed at 12 months prior to a booster dose of the 13-valent pneumococcal conjugate vaccine (PCV-13), and at 24 months of age, using the Illumina Methylation 450 K assay and assessed for differences over time and between high and low vaccine responders. RESULTS: Our analysis revealed 721 significantly differentially methylated positions between 12 and 24 months (FDR < 0.01), with significant enrichment in pathways involved in the regulation of cell-cell adhesion and T cell activation. Comparing high and low vaccine responders, we identified differentially methylated CpG sites (P value < 0.01) associated with HLA-DPB1 and IL6. CONCLUSION: These data imply that epigenetic changes that occur during early childhood may be associated with antigen-specific antibody responses to pneumococcal vaccines.

Complex Linkage Disequilibrium Effects in HLA-DPB1 Expression and Molecular Mismatch Analyses of Transplantation Outcomes.

BACKGROUND: HLA molecular mismatch (MM) is a risk factor for de novo donor-specific antibody (dnDSA) development in solid organ transplantation. HLA expression differences have also been associated with adverse outcomes in hematopoietic cell transplantation. We sought to study both MM and expression in assessing dnDSA risk. METHODS: One hundred three HLA-DP-mismatched solid organ transplantation pairs were retrospectively analyzed. MM was computed using amino acids (aa), eplets, and, supplementarily, Grantham/Epstein scores. DPB1 alleles were classified as rs9277534-A (low-expression) or rs9277534-G (high-expression) linked. To determine the associations between risk factors and dnDSA, logistic regression, linkage disequilibrium (LD), and population-based analyses were performed. RESULTS: A high-risk AA:GX (recipient:donor) expression combination (X = A or G) demonstrated strong association with HLA-DP dnDSA (P = 0.001). MM was also associated with HLA-DP dnDSA when evaluated by itself (eplet P = 0.007, aa P = 0.003, Grantham P = 0.005, Epstein P = 0.004). When attempting to determine the relative individual effects of the risk factors in multivariable analysis, only AA:GX expression status retained a strong association (relative risk = 18.6, P = 0.007 with eplet; relative risk = 15.8, P = 0.02 with aa), while MM was no longer significant (eplet P = 0.56, aa P = 0.51). Importantly, these risk factors are correlated, due to LD between the expression-tagging single-nucleotide polymorphism and polymorphisms along HLA-DPB1. CONCLUSIONS: The MM and expression risk factors each appear to be strong predictors of HLA-DP dnDSA and to possess clinical utility; however, these two risk factors are closely correlated. These metrics may represent distinct ways of characterizing a common overlapping dnDSA risk profile, but they are not independent. Further, we demonstrate the importance and detailed implications of LD effects in dnDSA risk assessment and possibly transplantation overall.

Permissive HLA-DPB1 mismatches in HCT depend on immunopeptidome divergence and editing by HLA-DM.

In hematopoietic cell transplantation (HCT), permissive HLA-DPB1 mismatches between patients and their unrelated donors are associated with improved outcomes compared with nonpermissive mismatches, but the underlying mechanism is incompletely understood. Here, we used mass spectrometry, T-cell receptor-ß (TCRß) deep sequencing, and cellular in vitro models of alloreactivity to interrogate the HLA-DP immunopeptidome and its role in alloreactive T-cell responses. We find that permissive HLA-DPB1 mismatches display significantly higher peptide repertoire overlaps compared with their nonpermissive counterparts, resulting in lower frequency and diversity of alloreactive TCRß clonotypes in healthy individuals and transplanted patients. Permissiveness can be reversed by the absence of the peptide editor HLA-DM or the presence of its antagonist, HLA-DO, through significant broadening of the peptide repertoire. Our data establish the degree of immunopeptidome divergence between donor and recipient as the mechanistic basis for the clinically relevant permissive HLA-DPB1 mismatches in HCT and show that permissiveness is dependent on HLA-DM-mediated peptide editing. Its key role for harnessing T-cell alloreactivity to HLA-DP highlights HLA-DM as a potential novel target for cellular and immunotherapy of leukemia.

HLA-DPB1 and HLA-C alleles are associated with leprosy in a Brazilian population.

Despite intense efforts, the number of new cases of leprosy has remained significantly high over the past 20 years. Host genetic background is strongly linked to the pathogenesis of this disease, which is caused by Mycobacterium leprae (M. leprae), and there is a consensus that the most significant genetic association with leprosy is attributed to the major histocompatibility complex (MHC). Here, we investigated the association of human leukocyte antigen (HLA) class I and II genes with leprosy in a Brazilian population encompassing 826 individuals from a hyperendemic area of Brazil; HLA typing of class I (-A, -B, -C) and class II (-DRB1, -DQA1, -DQB1, -DPA1, and -DPB1) loci was conducted. Initially, the associations were tested using the chi-square test, with p-values adjusted using the false discovery rate (FDR) method. Next, statistically significant signals of the associations were submitted to logistic regression analyses to adjust for sex and molecular ancestry data. The results showed that HLA-C*08, -DPB1*04, and -DPB1*18 were associated with protective effects, while HLA-C*12 and -DPB1*105 were associated with susceptibility to leprosy. Thus, our findings reveal new associations between leprosy and the HLA-DPB1 locus and confirm previous associations between the HLA-C locus and leprosy.

Proteinase 3 Autoreactivity in Anti-Neutrophil Cytoplasmic Antibody-associated vasculitis-Immunological versus clinical features.

ANCA-associated vasculitis (AAV) is a group of chronic inflammatory diseases of small- and medium-sized vessels, which are broadly subdivided based on organ manifestations and disease-specific autoantibodies. The so called anti-neutrophil cytoplasmic antibodies (ANCA) mostly target one of the enzymes, proteinase 3 (PR3) or myeloperoxidase (MPO). Accumulating genetic data demonstrates that these two autoantibodies discriminate two distinct disease entities, more so than the clinical subdivision which is mainly criteria-based. Treatment of AAV includes heavy immunosuppression and is guided by which organs that are involved. Generally, patients with PR3-ANCA display higher risk for disease relapse than patients with MPO-ANCA. In this review, we will focus on the autoimmune features of PR3+ AAV and our current understanding of its triggers and the potential translation into clinical practice.

HLA-DPB1 Reactive T Cell Receptors for Adoptive Immunotherapy in Allogeneic Stem Cell Transplantation.

HLA-DPB1 antigens are mismatched in about 80% of allogeneic hematopoietic stem cell transplantations from HLA 10/10 matched unrelated donors and were shown to be associated with a decreased risk of leukemia relapse. We recently developed a reliable in vitro method to generate HLA-DPB1 mismatch-reactive CD4 T-cell clones from allogeneic donors. Here, we isolated HLA-DPB1 specific T cell receptors (TCR DP) and used them either as wild-type or genetically optimized receptors to analyze in detail the reactivity of transduced CD4 and CD8 T cells toward primary AML blasts. While both CD4 and CD8 T cells showed strong AML reactivity in vitro, only CD4 T cells were able to effectively eliminate leukemia blasts in AML engrafted NOD/SCID/IL2Rγc-/- (NSG) mice. Further analysis showed that optimized TCR DP and under some conditions wild-type TCR DP also mediated reactivity to non-hematopoietic cells like fibroblasts or tumor cell lines after HLA-DP upregulation. In conclusion, T cells engineered with selected allo-HLA-DPB1 specific TCRs might be powerful off-the-shelf reagents in allogeneic T-cell therapy of leukemia. However, because of frequent (common) cross-reactivity to non-hematopoietic cells with optimized TCR DP T cells, safety mechanisms are mandatory.

Immunopeptidome Analysis of HLA-DPB1 Allelic Variants Reveals New Functional Hierarchies.

HLA-DP alleles can be classified into functional T cell epitope (TCE) groups. TCE-1 and TCE-2 are clearly defined, but TCE-3 still represents an heterogeneous group. Because polymorphisms in HLA-DP influence the presented peptidome, we investigated whether the composition of peptides binding in HLA-DP may be used to refine the HLA-DP group classification. Peptidomes of human HLA-DP-typed B cell lines were analyzed with mass spectrometry after immunoaffinity chromatography and peptide elution. Gibbs clustering was performed to identify motifs of binding peptides. HLA-DP peptide-binding motifs showed a clear association with the HLA-DP allele-specific sequences of the binding groove. Hierarchical clustering of HLA-DP immunopeptidomes was performed to investigate the similarities and differences in peptidomes of different HLA-DP molecules, and this clustering resulted in the categorization of HLA-DP alleles into 3-DP peptidome clusters (DPC). The peptidomes of HLA-DPB1*09:01, -10:01, and -17:01 (TCE-1 alleles) and HLA-DPB1*04:01, -04:02, and -02:01 (TCE-3 alleles) were separated in two maximal distinct clusters, DPC-1 and DPC-3, respectively, reflecting their previous TCE classification. HLA-DP alleles categorized in DPC-2 shared certain similar peptide-binding motifs with DPC-1 or DPC-3 alleles, but significant differences were observed for other positions. Within DPC-2, divergence between the alleles was observed based on the preference for different peptide residues at position 9. In summary, immunopeptidome analysis was used to unravel functional hierarchies among HLA-DP alleles, providing new molecular insights into HLA-DP classification.

Genetic Susceptibility to Systemic Sclerosis in the Greek-Cypriot Population: A Pilot Study.

Background: Systemic Sclerosis (SSc), also known as scleroderma, is an autoimmune rheumatic disease, which is clinically subdivided into two major subgroups; limited (lcSSc) and diffuse cutaneous scleroderma (dcSSc). Even though the SSc etiologies remains unclear, some HLA and non-HLA genetic variants have been associated with the disease. Aim: This study was designed to evaluate the associations between several HLA-related genetic variants and SSc in the Greek-Cypriot population. Methods: Forty-one SSc patients and 164 controls were genotyped at 18 selected single nucleotide polymorphisms (SNPs) using restriction fragment length polymorphism analyses, Sanger sequencing, and a multiplex SNaPshot minisequencing assay. Logistic regression analysis under the log-additive model was used to evaluate all possible associations between these SNPs and SSc; nominal statistical significance was assumed at p < 0.05. Results: Associations of SSc with SNPs rs3117230, rs3128930, and rs3128965 within the HLA-DPB1 and HLA-DPB2 regions were observed in the Greek-Cypriot population at the level of p < 0.05. However, none of these associations survived a Bonferroni correction. The direction of the effect is consistent with the direction reported in previous studies. In addition, allele frequencies of the majority of the selected SNPs in the Greek-Cypriot population are similar to those reported in the European population. Conclusion: This study initiates the genetic investigation of SSc in the Greek-Cypriot population, a relatively small newly investigated population. Further investigation with a larger sample size and/or additional SSc susceptibility loci may confirm the association of some of these variants with SSc in the Greek-Cypriot population that could potentially be used for predictive testing.

Donor selection in a pediatric stem cell transplantation cohort using PIRCHE and HLA-DPB1 typing.

BACKGROUND: New strategies to optimize donor selection for hematopoietic stem cell transplantation (HSCT) have mainly been evaluated in adults, but the disease spectrum requiring HSCT differs significantly in children and has consequences for the risk of complications, such as graft-versus-host disease (GvHD). PROCEDURES: Here we evaluated whether HLA-DPB1 and Predicted Indirectly ReCognizable HLA-Epitope (PIRCHE) matching can improve donor selection and minimize risks specific for a pediatric cohort undergoing HSCT in Berlin between 2014 and 2016. RESULTS: The percentage of HLA-DPB1-mismatched HSCT in the pediatric cohort was in line with the general distribution among matched unrelated donor HSCT. Nonpermissive HLA-DPB1 mismatches were not associated with a higher incidence of GvHD, but the incidence of relapse was higher in patients undergoing HSCT from HLA-DPB1-matched transplantations. High PIRCHE-I scores were associated with a significantly higher risk for developing GvHD in patients undergoing HSCT from nine of ten matched unrelated donors. This finding persisted after including HLA-DPB1 into the PIRCHE analysis. CONCLUSIONS: Implementing PIRCHE typing in the donor selection process for HSCT in children could particularly benefit children with nonmalignant diseases and support further validation of PIRCHE-based donor selection in a larger number of children treated at different sites.

Response to hepatitis B vaccination is co-determined by HLA-DPA1 and -DPB1.

BACKGROUND AND AIMS: No report explored the combined effects of HLA-DPA1 and -DPB1 with long-term response to hepatitis B (HB) vaccination (HBVac). The specific aims of the study were to assess the combined effects and relative contributions of DPA1 and DPB1 genes. METHODS: The cases were 152 adolescents who had undetectable (<1.0 mIU/mL) post-booster anti-HBs titers and the controls were adolescents who had residual anti-HBs ≥ 10 mIU/mL at aged 16 years (n = 207) or had detectable (≥1.0 mIU/mL) anti-HBs titers after booster HBVac (n = 481). HLA-DPA1 and -DPB1 genotypes were determined by sequence-based typing. RESULTS: HLA-DPA1*01:03:01 was correlated with lower ORs of undetectable anti-HBs titers, while -DPA1*02:02:02 and -DPB1*05:01:01 were correlated with higher ORs. The ORs for HLA-DPA1*01:03:01-DPB1*05:01:01 and DPA1*02:02:02-DPB1*protective combinatory types were significantly less than 1.0. As compared with subjects who had no protective allele, the adjusted ORs (95% CI) were 0.545 (0.328-0.906), 0.350 (0.174-0.702), and 0.122 (0.058-0.257), for subjects who had protective alleles on DPA1only, DPB1 only, and both genes, respectively. Analyses of amino acid polymorphisms showed that subjects who carried Arg81-Pro158-Val191-Pro259α + Met234ß and Gln62-Arg82α + Met234ß combinations had 4.3-to-4.6 folds of risks. CONCLUSION: Both DPA1 and DPB1 genes contribute to the persistence of immunological response to primary infantile HBVac. The effects of HLA-DP risk alleles were dominated by the protective alleles and there were significant gene-gene interactions. Our findings provide evidences for the design of more potent HB vaccine.

Impact of HLA-DPB1 Matching on Outcome of Unrelated Transplant for Hematologic Malignant Diseases: A Systematic Review and Meta-analysis.

OBJECTIVE: Human leukocyte antigen match is the most important donor factor affecting transplant outcome. The HLA-DPB1 mismatch on the clinical outcome of hematopoietic stem cell transplant (HSCT) is less clear. This study is the first meta-analysis to investigate the impact of HLA-DPB1 loci mismatch on clinical outcome after unrelated donor HSCT for hematologic malignant disease. METHODS: We electronically searched the PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and a related database (January 1995-December 2018) for all relevant articles. Comparative studies were carried out to investigate the impact of HLA-DPB1 loci mismatch on clinical outcome after unrelated donor HSCT, that is, the disease-free survival, engraftment, graft-vs-host disease, relapse, and transplant-related mortality (TRM). We performed a meta-analysis using Review Manager 5.3.5 software and adopted funnel plot regression to assess the publication bias. RESULTS: A total of 1570 articles were retrieved; 21 studies including 27,852 patients were assessed. Pooled comparisons of studies found that the HLA-DPB1-mismatched group had a lower rate of disease-free survival than the DPB1-matched group and lower overall survival in non-T cell-depleted transplant than the DPB1-matched group. The DPB1-mismatched group has higher incidence of acute graft-vs-host disease (aGVHD) and severe (≥ III degree) aGVHD, lower relapse rate, and higher TRM. Moreover, compared with 1-antigen mismatch, 2-antigen mismatch in DPB1 had a higher risk of TRM and a lower relapse rate, and the nonpermissive DPB1 mismatch had significantly higher rate of severe aGvHD and lower rate of disease relapse. CONCLUSIONS: This analysis confirmed that HLA-DPB1 has important influence on survival and transplant-related complications during unrelated donor HSCT, and HLA-DPB1 donor selection strategies have been proposed based on personalized algorithm.

HLA alleles, especially amino-acid signatures of HLA-DPB1, might contribute to the molecular pathogenesis of early-onset autoimmune thyroid disease.

The major histocompatibility complex region has been suggested to play an important role in the development of autoimmune thyroid disease (AITD). In this study, we investigated the associations of human leukocyte antigen (HLA) alleles and amino acid variants of HLA with early-onset AITD. HLA class I and class II genes were analyzed in 116 Korean children with AITDs (Graves' disease [GD]: 71, Hashimoto's disease [HD]: 45) and 142 healthy controls. HLA-B*46:01 (OR = 3.96, Pc = 0.008), -C*01:02 (OR = 2.51 Pc = 0.04), -DPB1*02:02 (OR = 3.99, Pc = 0.04), and -DPB1*05:01 (OR = 4.6, Pc = 0.003) were significantly associated with GD, and HLA-A*02:07 (OR = 4.68, Pc = 0.045) and -DPB1*02:02 (OR = 6.57, Pc = 0.0001) with HD. The frequency of HLA-DPB1*05:01 was significantly higher in GD patients than in HD patients (Pc = 0.0005). Furthermore, differences were found between patients with Thyroid associated ophthalmopathy (TAO) and those without TAO in the distribution of HLA-B*54:01 (8.6% vs. 30.6%, P = 0.04) and -C*03:03 (37.1% vs. 11.1%, P = 0.02). In the analysis of amino acid variants of HLA molecules, both Leu35 (OR = 23.38, P = 0.0002) and Glu55 (OR = 23.38, P = 0.0002) of HLA-DPB1 were strongly associated with GD and showed different distributions between GD and HD (P = 0.001). Our results suggest that HLA alleles, especially amino-acid signatures of the HLA-DP ß chain, might contribute to the molecular pathogenesis of early-onset AITD.